Bottle yeast harvest - have I messed up?

[morethanworts]

I added 100ml of 1.040 wort to 25ml dregs of a Belgian tripel last night and put it on the stir plate at 21C, with some nutrient.

It's only now that I read on BYO that perhaps I should have put as little as 5 or 6ml wort onto the yeast as a first step and at only 1.015-1.020. I'm sure I've read of people using a much bigger first addition than that. :hmm:

Three questions then please:
Is there practically zero chance of success in what I've done?
Is there anything I can or should do (in the absence of another bottle)?
How long should I give it to see if anything happens (ie at what point has it failed)?

 

[rpt]

I harvested the yeast from a bottle of Hopback Summer Lightning. I used 200mL of 1.020 wort and kept it at 22C. After 2 days I pitched the whole lot into about 1.3L of 1.040 wort. After a few hours there were obvious signs of fermentation. I don't think there was much evidence of anything happening in the initial 200mL. I think you will probably be OK but you will want to step up soon. 1.020 stresses the yeast less since sitting in a bottle will already have stressed it. 1.040 wort allows more growth.

 

[morethanworts]

Thanks rpt.

Day 4 and there looks to be lots of clumpy stuff (yeast I hope!) floating around in the conical, after stepping up with a further 500ml @1.040 two days ago, without decanting. I didn't see CO2 rising in either of them; at least I never caught it in the act. There are no traces of krausen on the flask either, though the stir plate has been on continuously and keeping a good whirlpool going. This time yesterday, it still looked and smelt like unfermented wort, though the smell has now changed too.

I wish I'd seen it 'in the act', but I guess I will crash cool it now, let it clear down, and test the gravity before stepping up to 3L. Should I expect big attenuation?

I'm deducing that if there is as much yeast floating around as there is, with no visible activity, and the smell has now changed, then I must have missed the main fermentation stage; this is not just still some big exponential growth phase?

EDIT - I decided to take a gravity reading shortly after posting. It's hardly moved from the original 1.040, so I can only think that all this clumpy yeast is still growing and it's not really started the main business yet. Back on the stir-plate, 22C...

The tiny dreg left in the bottom of the sample jar now carries much of the distinctive taste and smell of the original beer, despite it not being off the mark, gravity wise! Hopefully a good sign, if it does get properly going.

 

[morethanworts]

Quick update on this. There is so much yeast in there this morning, that the DIY stirplate is now struggling to keep a whirlpool going, but it still doesn't seem to be fermenting. I hope this is just a very protracted growth phase.

Anyone had yeast grow, but then not do the business?

Wait and see, patience, I know...

 

[morethanworts]

No yeast experts in?

After 4 days on the second step, I've grown loads of yeast (it almost looks like a slush puppy!) but no fermentation.

This is my guess, based on checking the 'Yeast' book (White/Zainasheff) but I'd be grateful for any thoughts:

I'm guessing that starting with 1.040 wort, rather than 1.020 (considering it was a bottle harvest) AND probably too much of it, has led to loads of growth but low viability. On the upside, the unfermented starter has gained much of the characteristic smell and taste of the original beer, which I am hoping at least proves that it was the primary strain; if I get to do it again, this is a good sign.

Before abandoning the attempt, considering I don't have another bottle with which to work at the moment, I'm wondering whether I could still step up the starter again to 3L, and pitch it into the main batch to add all the flavours and aroma during the lag/growth phases, before then dropping in some us-05 to do the main job.

What do you think?

 

[brewtim]

My thoughts are that if you have any doubts about a yeast, then just bin it and start with fresh, for the cost of a packet of fresh, it's not worth risking losing a batch and all the hours that went into it.

I've just had a batch that soured from my own bottle harvested yeast, I should have binned it at the 2nd step starter stage as it started to go a bit funky then!

:sick:

 

[Asalpaws]

Hi G, are you sure it's not fermented out if it smells like beer it's probably fermenting! Have you tasted it? I always taste mine, if it tastes sour I ditch it. Seems to be a very hit and miss process, I've only got as far as a full batch twice (Saison Dupont and Delerium Tremens), other times there has been no visable fermentation (can take up to 5 days to start) or it has fermented but tastes sour and infected. When it ferments you get a mini kreuzen on the starter with a scum line just like in a FV. If it tastes good and seems to be fermenting would be worth a go, perhaps do a split batch, ferment other half with a commercial yeast so you wouldn't loose the whole batch if it didn't work. It's possible you have the yeast but because of stress it has formed "small mutants" which don't attenuate well, in which case adding in US 05 later might work. All the best T

 

[morethanworts]

Thanks both! Some helpful thoughts there.

Well I checked the gravity 2 nights ago and it hadn't budged, although it did smell and taste much like the original, just much much sweeter! I don't like to go interfering with starters, for obvious reasons, but I think I will give it until tomorrow and take another gravity reading (and taste) to be sure. Both the successful starters I've done, with WY3787, smelled pretty bad (I didn't taste them) and I've read that starters do not usually taste like good beer. Perhaps 'sour' is a different thing, though.

The main cost on brewday is always my time and fitting it around a family schedule, so I'd be unlikely to bother with a half batch, if I was bothering at all, and I'm not sure I could keep a split batch in two FVs at the right temperature very easily.

There looks to be SO much yeast in that flask now, that it's hard to believe it will suddenly kick into life, if it hasn't already. I will give it until tomorrow, but I guess that if there's any chance I might pitch it, only to throw in some US-05 shortly after, I don't want it sat under unfermented sugary, alcohol-free wort at 22C for any longer than necessary.

 

[rpt]

How do you know it is yeast that you can see? It really should have attenuated by now. You need a low gravity wort (something like 1.008 I think) plus a good supply of oxygen to get yeast growth without creating ethanol. Even in this case the yeast must be eating the sugar so the gravity should fall. At least that's my understanding from a quick look at the Yeast book.

 

[Asalpaws]

Although starters don't taste like proper beer I find they do taste similar but infected starters taste very unpleasant . I agree time is always the biggest "cost" of brewing.

Recently I've just used commercial yeast as I dare not waste a brew day, however it's pretty straight forward to split the wort 50:50 or 25:75 into two FVs if you want to try an experimental yeast + a commercial yeast. That way you should end up with some good beer. T

 

[morethanworts]

How do you know it is yeast that you can see?

I guess I don't! Looks like yeast to me though.

I can fit a demijohn or two above the FV in the brew fridge, so maybe I will yet do a split batch, though when I did a temperature test just with water in a DJ before, on a shelf above, it showed that I needed to improve airflow (ie shallower shelf) to allow warm air to rise, to keep the DJ anywhere close to the FV temp.

Here's a question I've always been afraid to ask, considering I've been using hydrometers for over 20 years! Is there any way that the shear density of yeast in solution can distort (upwards) the gravity reading? If you collected a whole sample jar of yeast slurry from the bottom of an FV, it would surely be thicker (and read higher) than the beer above it. So at what point does this cease to be a problem, when taking a reading? Do you trust your reading regardless of how much yeast is in solution?

 

[Asalpaws]

Interesting point, anything truly in solution is going to affect the specific gravity upwards. If you could crash cool the yeast out and measure the wort left over is the only real way of checking. At least that way you don't risk contaminating the yeast just decant it into a trial jar. T

 

[rpt]

I don't think yeast is in solution but in suspension but I'm not sure how that affects the hydrometer.

 

[morethanworts]

I don't think yeast is in solution but in suspension but I'm not sure how that affects the hydrometer.

Suspension is probably the word I was after. You were right to question whether it was yeast I could see as well. On closer inspection tonight, I have described to you a massive infection! once the stir plate had been off a while, it clumped together in a very unyeasty gelatinous gunk and some spores were forming up the top too. :sick: Needless to say, a thorough clean up has begun.

The answer to my original question is certainly YES!

Looking forward to receiving a nice healthy pack of WY3787 in the post tomorrow.

 

[Asalpaws]

Oh well, that has definitely happened to me with dregs of Sam Smiths - Yorkshire Stingo: fungus city. It is a hit and miss process, makes you think that commercial brewers are not as careful with sanitation as home brewers but it's probably the fact that if there's no viable yeast even one cell of fungus or bacteria is going to grow and take over. Better luck next time. T